MathDB

47

Part of 1982 IMO Longlists

Problems(1)

The sum of second derivatives of fractions k pi/4 (k odd)

Source: IMO LongList 1982 - P47

5/16/2011
Evaluate sec⁡′′π4+sec⁡′′3π4+sec⁡′′5π4+sec⁡′′7π4\sec'' \frac{\pi}4 +\sec'' \frac{3\pi}4+\sec'' \frac{5\pi}4+\sec'' \frac{7\pi}4. (Here sec⁡′′\sec'' means the second derivative of sec⁡\sec).
calculusderivativetrigonometryalgebra proposedalgebra